RefPipeSizer

Pro

Refrigeration pipe sizing for ammonia, CO2, and A2L systems.

Overview

RefPipeSizer sizes refrigerant lines the way industrial designers do: by saturated-temperature penalty, velocity, oil return, and flash-gas margin. It covers eleven refrigerants — R-717 (ammonia), subcritical R-744 (CO2), the A2L family (R-32, R-454B, R-1234yf, R-1234ze(E), R-455A, R-454C), and legacy A1s — across six line duties including pumped-liquid supply and two-phase wet suction return for overfeed systems.

Key features

• Dry suction, discharge, liquid, hot-gas defrost, pumped liquid, and wet suction return lines
• ΔT saturation-penalty criterion with Darcy-Weisbach / Colebrook friction, per ASHRAE practice
• Oil-return riser check at minimum part load for miscible-oil refrigerants
• Flash-gas guard on liquid lines (friction plus static rise vs available subcooling)
• Lockhart-Martinelli two-phase sizing for overfeed wet returns
• Steel Sch 40/80 and ACR copper tables with material rules (ammonia and CO2 are steel-only)
• CoolProp-derived saturation properties; zeotropic blends use dew and bubble curves correctly

How to use it

1. 1

   Click RefPipeSizer on the RIME ribbon (Refrigeration panel).

2. 2

   Pick the refrigerant and line type, and enter load, SST, and SCT.

3. 3

   Adjust superheat, subcooling, equivalent length, and criteria as needed.

4. 4

   Calculate — the smallest passing size is recommended with the full candidate table.